The Male Brain (2010) is a neuroscientist’s account of the interplay between hormones and brain development that shapes the formation and growth of male brains and behavior. Based on decades of research, it argues that the roots of many masculine stereotypes can be seen in neurobiology, and that hormones shape the male brain and outlook for a lifetime.
Introduction: Discover the power of hormones in shaping male brains and behavior
Table of Contents
For the first eight weeks of life, all brains look female. But from this pivotal moment onward, things radically change for about half of those embryos.
At eight weeks, the male embryo receives a surge of the hormone testosterone, which kicks off a massive transformation and grows a male brain and body. From the womb through old age, hormones drive everything from growth spurts to risky behavior, sex drive to bonding with kids.
So whether you have a male brain – or just interact with them – this summary can help answer the question, “Why does he do that?” based on a neuroscientist’s decades of research.
A Male Brain Is Born
From eight weeks of gestation onward, three hormones have an outsized impact on the development of the male brain. The first is testosterone, whose rises and drops affect everything from male brain development to sex drive to hair growth. The second is vasopressin, the male bonding hormone. It influences things like his mate-guarding behaviors and bonding.
The third has a complex name and a complex function. Called Müllerian inhibiting substance, it builds many of the circuits in the male brain that are associated with traditional masculinity. It shrinks any remnants of female structures in the developing embryo to grow a male body. And it creates the neural connections for things like muscular action, exploratory behavior, and competitive aggression.
This hormone trio, along with a few other helpers, grows a brain that ends up looking significantly different from the female brain. The amygdala – the part of the brain that handles fight or flight reactions to threats, becomes larger and contains more neurons in the male brain. Their circuits for defending territory are larger, too, while their communication circuits and memory centers have far fewer connections than female brains.
The male brain is bathed in high levels of these hormones until birth and beyond, and they shape his behavior during those early days. For the first year of life, his testosterone levels are on par with an adult man’s. This inhibits brain circuits for recognizing facial expressions, which are smaller than his female-brain counterparts.
By seven months, he can recognize facial expressions of anger or fear in adults, but by twelve months his sensitivity to them plummets. With an immunity to signs of danger or warning, and a neurological drive to explore and track motion, it can challenge even the most attentive caregiver to keep up and keep him safe.
Without brain structures in place to put on the emotional brakes, he’ll likely be easily worked up – and harder to soothe. His outbursts will last longer, and he’ll make less eye contact during these emotional exchanges.
At the end of the first year, his hormone levels decrease as the male brain becomes a juvenile. For the next decade, give or take, he’ll have low, steady hormone levels like his female-brained counterparts. But his brain has been completely structured under the hormonal influence, and his on-the-go, rough-and-tumble impulses will continue through boyhood.
Boyhood Brain and Puberty
Boyhood is as close as the male brain will be to his female-brained counterparts since the first eight weeks as an embryo. Behaviorally, however, the distinct characteristics between male and female brains make for some striking differences.
His play will likely look far different from his female-brained peers. While female brains are practicing their verbal communication, consensus-building, and social skills on the playground, male brains have a different focus.
With more structures and neurons controlling muscular activity and spatial awareness, pecking order and hierarchy, his play often looks chaotic and rough. Racing, competing, and gaming satisfy his need for continual challenges and tests. Winning is everything – and it gives his brain a hit of dopamine, the body’s reward chemical, when he does.
As anyone who has cared for a male-brained infant or child knows all too well, he’ll also have a hard time putting the brakes on playing with his own penis. Partly, this is the influence of those high levels of testosterone in infancy. While his peers with female brains are getting dopamine rewards from communicating and connecting, he gets a massive rush from the pleasure centers of his brain when playing with his penis because those circuits are far stronger.
So if a young female brain experiences dopamine withdrawal when separated from friends, the same is true for young boys when they can’t touch themselves. The effects can be as strong as withdrawals from drugs like cocaine.
At puberty, some of this will change – but for male-brained teens, it means much of it intensifies. As testosterone levels soar, it brings on everything from acne and body hair to uncontrollable erections.
His lack of rewards from the communication centers of his brain continue, but his aggression and need to challenge authority dials up. His physical growth quickens at this time, too, and his need for independence skyrockets. Many who interact with a male-brained teen find him bored, uncommunicative, and resistant.
These core behaviors associated with rebellious teen years are, in fact, hormonally driven. He isn’t acting bored; he is bored. His brain doesn’t light up with communication, but with action, challenge, and risk. With his prefrontal cortex still forming, he doesn’t have full control over his behavior, either. The prefrontal cortex understands cause and effect. So he literally can’t exactly grasp the consequences of skipping homework in favor of video games, or what might happen if he misses the trampoline while jumping off the roof.
The increase in testosterone also kicks off sexual drive. Given the sheer amount of neurons in the male brain dedicated to sexuality, this new obsession will impact the male brain for decades to come.
Sexuality and the Male Brain
Young boys get dopamine rushes from playing with their penises, but teen and adult male brains get far more. Testosterone has driven this sexuality reward system, and when sexuality awakens in puberty, it can feel like a force of nature.
That’s in large part because it is. The hypothalamus, the structure deep in the brain that kicked off puberty, is conducting a hormonal symphony in the maturing male brain. His hypothalamus drives his mate-seeking behavior, and when the male brain notices a potential sexual partner in the room, it lights up like a Christmas tree. All those motion-tracking and environmental exploration circuits developed in infancy and childhood now scan the environment for potential partners. In mate-seeking mode, the teen and adult male brain can seem to have only one focus. Biologically speaking, this isn’t far off.
If testosterone were his only hormone, this mate-pursuing mode might last forever. But vasopressin, the male bonding hormone, is also rising. Like oxytocin in female brains, vasopressin in male brains kicks off the formation of intimate relationship bonds. The drive for fight and challenge that was dialed up by his amygdala can be tamed with higher levels of vasopressin. This hormone is released with sustained touching, kissing, and physical contact, and it bonds the male brain to significant others.
When mate-pursuing mode gives way to the mated mind, this vasopressin reward system transforms the brain once again. When the male brain first has sex, a part of the hypothalamus memorizes his partner’s smell, their touch, and their sounds – and imprints them deep in the brain. The huge dopamine reward he gets at the same time means he associates this experience with immense pleasure. If his brain has high levels of vasopressin, and receptors to absorb it, this can form the male brain into a monogamous mind. He bonds intimately, reinforced through vasopressin and dopamine by touching, cuddling, and sex.
Those with low levels of vasopressin, or fewer vasopressin receptors in the brain, can seem immune to such intimate bonding. Those male brains that form fewer attachments and stay in mate-pursuit mode don’t get the same neural rewards for intimacy. Testosterone fuels the search, and the amygdala stays on alert, driving an endless hunt for sex.
Many of the stereotypes of male behavior seem to be illustrated in these descriptions of hormonal differences – and have real biological roots. Sensitivity to vasopressin and bonding can become a huge factor in whether he makes the transition to a mated brain and, possibly, a dad brain.
Mated and Dad Brains
When a male brain in mate-pursuit mode meets an actual mate, things get intense. Very deep, near the center of his brain, a place called the ventral tegmental area begins pumping out dopamine – and his pleasure centers light up. Along the way, they get mixed with testosterone, driving sex brain, and vasopressin, driving bonding brain. The mix can be as heady as it is all-consuming. The male brain in mating gets a literal high.
When he’s separated from his mate, the male brain goes through more changes. His NAc, or nucleus accumbens, the area of the brain that anticipates reward and pleasure, also lights up with these hormones. When they’re apart, the male brain is prone to anticipation and distraction, obsessing over and preparing for the next encounter. This, too, is like an addictive fuel, driving the pleasure centers to crave more encounters, to release more hormones, to create more pleasure, and so on.
Whether together or apart, the male brain circuits don’t stop scanning the room for other potential mates. Those circuits don’t shrink with pair bonds. His sexual circuits will light up as if on autopilot – and with high levels of testosterone, they pretty much are.
But they’re also driving mate-guarding behaviors. His amygdala, driving fear reactions, ramps up his sensitivity to rejection and intensifies his feelings of love. His hypothalamus is in on the act, too. His brain puts him on red alert, and drives his territorial defense instincts to kick in around his mate. The ramped-up aggression becomes mate-guarding, as his brain instinctually guards his bond to maintain this newfound vasopressin and dopamine happiness.
When the mated male mind learns that he will become a father, yet another powerful transformation begins. It might be the first time he sees his child on an ultrasound, or not until he holds his newborn, but his bonding hormone vasopressin soars in these moments and forges a deep bond. Many male brains evolve as a pregnancy progresses and have parallel emotional, physical, and hormonal shifts. That’s because their testosterone levels begin to drop off sharply, while their levels of a hormone called prolactin rise.
Around the world, fathers who have a more intimate role in pregnancy, childbirth, and fatherhood have larger drops in testosterone levels. This may be because hormonal communications between partners via smells, touch, and kissing ramp up signals of looming parenthood – and both brains restructure in preparation.
Dad’s motion tracking and action-tuned brain centers evolve with this hormone change to care for active children and be on guard for their safety. His vasopressin and dopamine rushes are triggered by holding and playing with his child. Fathers are especially attentive during alone time with their kids, and these interactions make kids more self-confident. So the dad brain confers a powerful evolutionary advantage to their children.
Emotions, Communication, and the Male Brain
In the adult and mated male brain, testosterone has dampened their neural development around verbal communication and emotional memory. But their problem-solving circuits stay large and well connected. This can lead to the perception that male brains feel emotions less than female brains, but this isn’t true.
When a bonded male brain realizes his partner is upset, for instance, it immediately kicks into problem-solving mode. In male-female couples, this difference in instinctual responses fuels many conflicts. While a female-brained partner might crave communication and connection around her issue, their male-brained counterparts aren’t built for that. Their neural networks are hardwired to respond by offering solutions. It’s well intentioned, sure – but baffling to a partner who doesn’t understand why they can’t just listen.
A smaller difference in neural centers for emotional memory may drive other conflicts in male-female partnerships, too. The female brain’s emotional memory centers have more neurons to store away details about emotional encounters than the male hippocampus. So the perceptions of a situation in their relationship are recorded quite differently in each brain. These biological differences can be difficult to overcome in relationships, and they require each partner to develop strategies to adapt.
Female-brained partners have been hardwired by estrogen to tune into facial expressions and tones of voice from early infancy. But from childhood on, the male brain has suppressed these signals and damped his facial expressions to keep his emotions from being perceived by his peers. His compulsion to keep emotions from showing in his face can be interpreted as a lack of feeling, but it isn’t. His neural wiring simply keeps it from activating his expressions.
But it is socially acceptable in many cultures for men to express one particular emotion: anger. It’s triggered by the priming of high testosterone sensitivity and a large amygdala. And it has profound effects on those who interact with these male brains, negatively impacting careers, families, and communities.
As testosterone levels drop with age, however, this font of anger may dry up, giving way to a more nuanced expression of emotions.
The Aging Male Brain
From early adulthood, testosterone levels in the male brain have been slowly decreasing with age. They may have dropped more with fatherhood, or traced a slow arc downward. His levels of vasopressin – the bonding hormone – have also dropped, which can sometimes lead to relationship turmoil in aging men.
With less testosterone, his brain is becoming more like that of the postmenopausal female brain. He may be more sensitive to cuddling and touch. He may also begin to respond to oxytocin, and he becomes kinder, gentler, and far less prone to anger.
The aging male brain becomes more confident about expressing a full range of emotions, too. The circuits for defensiveness and anger that thrived in high testosterone now shrink, and the lion mellows. He may become less territorial, no longer quick to fight. He cares less for hierarchies, too, and about his place in the pecking order.
The aging male brain weighs the costs of victory at any price, and cares less about what others think of him. No longer obsessed with his own dopamine-fueled sexual pleasure, this brain is more tuned into the pleasure of his partner. He might even get as much pleasure from his partner’s orgasm at this age as he does from his own.
When levels of testosterone drop off too sharply, however, impotence and loss of sex drive can result. Both can be overcome with treatment – but may trigger anxiety and depression in the male brain, which has thrived on sex-driven stimulation since boyhood.
For aging male brains without a partner or close bonds, feelings of loneliness intensify. This isn’t character weakness but another biological imperative. Aging male brains thrive with the connected bonds that their female counterparts have nurtured since childhood. Staying connected to others actually improves physical health, lessens depression, and prolongs his life.
Male brains and bodies begin forming at eight weeks through a surge of the hormone testosterone. Throughout life, just a few hormones shape the neural structures and biological drives of the male brain. From his active boyhood through potential fatherhood, his levels of testosterone, vasopressin, and prolactin mold both his body and his intimate bonding. A drop in these hormones by old age brings him closer to the postmenopausal female brain, helping him forge the bonds that keep him happier and healthier.
Sure, I’d be happy to provide a brief review of the book “The Male Brain: A Breakthrough Understanding of How Men and Boys Think” by Louann Brizendine.
In “The Male Brain,” Louann Brizendine, a renowned neuropsychiatrist and author, delves into the intricate workings of the male brain, offering a comprehensive understanding of how men and boys think, behave, and interact with the world around them. This book provides a detailed analysis of Brizendine’s insights and findings, highlighting the key takeaways and implications for readers.
Brizendine’s book is divided into four parts, each exploring a different aspect of the male brain: the brain’s structure and function, the development of male cognition, the impact of testosterone on the brain, and the effects of gender and culture on male behavior. Throughout the book, Brizendine draws on extensive research and case studies to illustrate her points, providing a wealth of information on the male brain and its unique characteristics.
- Structure and Function: Brizendine explains that the male brain is composed of several distinct regions, each with its own specialized functions. For example, the amygdala, responsible for emotional processing, is larger in men than in women, while the hippocampus, essential for memory and spatial reasoning, is smaller.
- Development of Male Cognition: Brizendine discusses how the male brain develops over time, highlighting the significant differences between male and female brain development. For instance, boys’ brains develop more slowly than girls’, and the male brain continues to mature well into adulthood.
- Testosterone’s Influence: Brizendine explores the effects of testosterone on the male brain, demonstrating how this hormone influences everything from aggression and sexual behavior to cognitive function and emotional regulation.
- Gender and Cultural Factors: Brizendine examines how gender and cultural norms shape male behavior and cognition, showing how societal expectations can impact the development and expression of male identity.
Implications and Recommendations
- Improved Communication: Understanding the male brain can facilitate better communication between the sexes, as readers will learn to recognize and appreciate the unique cognitive and emotional characteristics of men and boys.
- Enhanced Empathy: By gaining insights into the male experience, readers will be better equipped to empathize with male loved ones, colleagues, and clients, fostering more effective relationships and a more harmonious society.
- Personal Growth: The book offers practical advice for men and boys seeking to optimize their cognitive and emotional functioning, as well as for women and girls looking to understand and connect with the men in their lives.
- Challenging Gender Stereotypes: By highlighting the diversity and complexity of male cognition and behavior, Brizendine challenges gender stereotypes and encourages a more inclusive and nuanced understanding of masculinity.
In “The Male Brain,” Louann Brizendine provides a comprehensive and accessible exploration of the male brain, offering a wealth of information and practical insights for readers. By understanding the unique characteristics of the male brain, readers can foster better relationships, improve communication, and promote personal growth and well-being. This book is a must-read for anyone interested in gender, cognition, and human behavior.